As explained on the previous page, the convention used in DOCJSLIB is that if a DIV element is labeled with a given ID, the ID of the IMG element within the DIV element is a concatenation of ID and the string "img". If the DIV's ID is "foo", for example, the IMG element within it will be labeled "fooimg". This is the reason we search above an IMG element that has an ID of id + "img".